Old Style Kerker 4-1 Fitment

[bikedave99]

I bought what was described by the seller as an older style Kerker 4-1 exhaust which apparently can retain the center stand tabs. Do any of you have any experience with this? This is what it looks like:

Here is a close up of the collector area:

I tried for a while to get it fitted last night and was having a time of it. I knew it wasn't going to be a walk in the park but figured I would get it eventually. I have a few pictures below of how it sits now but they aren't very good due to light. I was having a hard time getting one of the front header flanges to seat completely onto the cylinder seat, so I can't get a nut onto the stud. Either way a real pain just trying to get it dry-fit. Wondering if anyone had any tips or advice on getting it set. Also, does anyone recognize it and does it look like it will fit....? Pretty dang tight!

Not sure if it looks like it in this picture, but the center stand tab does fit between the tubes.

 

[1967vmax]

My bet is if you trim off those tabs it will fit.

 

[maxcruiser]

Never heard of an old style Kerker header and it looks the same as the one I used to have. Looks like the tabs need to come off. You may also need longer exhaust studs. I had to change mine when I changed to the Kerker exhaust.


Mike

 

[one2dmax]

Stud length will be fine. All Kerkers the same. Looks like it needs to have the right side tab cut off which is normal if you want the header to go all the way up and onto the rear down tubes. They suck to install.

Sean

 

[KJShover]

. They suck to install.

But sooooo worth it :biglaugh: unk:

 

[one2dmax]

I do not disagree!

 

[adamax]

I had a stock 1997, then I bought a carb set that were fitted with a jet kit and the kerker exhaust off a wrecked bike.
I remember I had to put slightly longer studs, I gave up the center stand, the rear pipes were slightly loose but silicone RTV worked wonders, the bike went horrendously fast... I was very pleased with the results. 10 years later I sold it to a guy who wrecked it and re-bought it from him, now it is under re-construction...

 

[bikedave99]

Thanks for the help guys! I will cut the tab(s) as necessary and make it work. To save me a little time, can someone tell me where to cut:

I'm guessing that silicone will be my friend as well. Oh, and is there a way to reinstall the heat shield on the back? I don't really see how as it mounts to the decorative cover piece... Seem like it will get too hot back there...
Oh, and if I give up on the stud length, where do you guys find the longer replacements?

 

[one2dmax]

Front head uses a longer stud but I have yet to need one. I usually cut it off close to the crossover of the frame that it's welded to. By leaving it there you can't get the header up enough to slip into the rear pipes very well. Heat shield will not be retained either. It does get warm there but never been an issue (and I've had my header GLOWING! - see the youtube burnout vids).

Sean

 

[bikedave99]

Thanks as always Sean, I'll get to hacking on it this weekend and will hopefully have a better report by Monday. I was able to get some new carb-airbox joints ordered and they arrived this past week so I will be trying to limp the remainder of the season before getting crazy on my possible ring/valve issue.

 

[adamax]

I remember I had to check the battery electrolyte more often, but again, I was so pleased with the results I did not care...

 

[bikedave99]

Success!

Well, I made it! After a number of alterations, it all came together. As you all said, there was some cutting that needed to be done. I will show you below what I needed to do. I wanted to do it with as little cutting as possible so I fitted the front headers and put a nut on one stud on each side. Then, without the rear downtubes in place I lifted the exhaust to see what it was hitting so I knew what to cut. I cut one tab and bent another and got it to fit up. I will be able to get it higher when I am ready but I wanted to maintain just a semblance of center stand usability in case I have an engine pull coming up. Once I was able to get the exhaust high enough in the back the front headers slipped into place and my front studs were plenty long enough. I put the down tube on the rear cylinders and tried to get it to slide on, not happening! So I took someone elses advice and cut three slits in the top of the rear slip joint and tried again... voila! First time, a little pressure and up it goes, everything settles in place and feels good! Anyway here are couple pics showing what I did:

So, after putting on my new carb joints and airbox I took it outside and fired it up. KJShover, you are right...... oh so worth it!! That is the baddest sounding idle I have heard. And a quick blip of the throttle makes the most pleasing rasp! I love it! I wiped the residue and oil off the pipe and went for ride yesterday, good fun! Love that sound! Thanks for the help guys!

Oh, and I see that Danny and others recommend a 1mm shim on the needles. Can someone explain where the shim goes so I put it on in the right order?

 

[Fire-medic]

I am sure I am not the first person to think about this, is there a way to relocate the centerstand tabs on that crosspiece so you could still have a centerstand function, even if it was just as a static use, and not something you could ride with it attached? I do not have my bike here, it's at the shop. I am thinking that you might need to change the corresponding tab piece on the centerstand to make this occur, since the design is a clevis-tab design. Or, you might need to relocate both of them... anyone who has contemplated this or who may have an idea, please inform me. I am investigating the purchase of a used Kerker 4/1. Seeing that this install required a bending of the left pair of mounts on the frame (or perhaps more-correctly, the inner of the left clevis pair) which would likely prevent any alignment of the left centerstand tab or rifling-home of the bolt even in a temporary install for service...

Thanks, guys.

 

[one2dmax]

That is quite possible but would require some welding work to be done!

 

[Fire-medic]

That is quite possible but would require some welding work to be done!

Thanks, Sean. I may not be a welder (I can braze OK) but I have friends who are great at it! I actually own 1/2 of a commercial TIG system at my friend's bike accessories shop, we bought it when a welding shop closed, but I have never taken the time to learn.

Sean, if I am at sea level here, and do decide to buy & fit the Kerker chrome 4/1, can I use the 147.5 main jets? Stock carbs, not even having the plugs in them removed yet. K&N #YA 1285 single filter, though I do have the K&N pods sitting on a shelf. Stock ignition, everything related to intake & ignition, engine innards, you get the idea. My friend is getting ready to reassemble my carbs.

 

[one2dmax]

With no other jetting changes (or airbox changes) you can leave the same jetting and should be good to go.

Sean

 

[Fire-medic]

With no other jetting changes (or airbox changes) you can leave the same jetting and should be good to go.

Sean

OK, just so I don't make a bone-headed mistake (fully-capable of that), when you mention, "...you can leave the same jetting," you are referring to installing the 147.5's and being able to use that for the Kerker 4/1? Sorry for asking, but sometimes I need to have things explained to me so I understand w/o ambiguity. Thank-you, Sean.

 

[one2dmax]

The Kerker when installed on an otherwise stock bike (with stock jetting) will be rich. So, the smaller mains typically get's them running better. So, if that's the situation we are talking about then you should be good.

 

[Fire-medic]

The Kerker when installed on an otherwise stock bike (with stock jetting) will be rich. So, the smaller mains typically get's them running better. So, if that's the situation we are talking about then you should be good.

Good, now I understand. I have to ask to avoid making expensive mistakes. Thank-you for the prompt feedback.

Sean, it may have been mentioned before, are you employed in the aerospace industry? What do you do? Or, is Morley's Muscle a fulltime thing?

 

[one2dmax]

My day job I work for Spirit Aerosystems (Formerly Boeing Wichita). We are the largest supplier of fuselage components in the world.

http://www.spiritaero.com/

The bike industry is getting much larger and faster for me but at this time i'm not wanting to make it a full time gig (if I did the pricing might have to go up lol).